Auxiliary fuel chamber



May 20, 1952 FIG! M. E. CHANDLER AUXILIARY FUEL CHAMBER Filed Sept. 18. 1947 FUEL- LEVEL.

IINVENTOR Patented May 20, 1952 FUEL cuisines 'lvliitoh TE. Chandler, New "Britain, Conn. Application September 18, 1945., serial Nb. 774,712 means. (01.123480) The object of this invention. isto provide an auxiliary supply chamber of fulfor carburetor or other charge forming device for starting purposes. 7 I v A further object is to -provide an auxiliary chamber of fuel that is filled during the normal operation of the engine, andmeans to use this auxiliary supply of fuel during the starting of theengine. H I V A A further object is to provide interconnections between either the throttle or choke mechanisms and this auxiliary supply chamber, so thatduring the normal operation of starting the engine the auxiliary supply of fuel can be made available for starting purposes, either-to supplement the fuel in the float chamber of the ca-rburetor or to provide fuel for engine operation until the engine fuel pump has been primed and iscapable of supplying fuel.

The quantity of fuel available in a -carburetor float chamber is a relatively smali quantity and is capable of operating the engine for -only an extremely short periodof time Furthermore, the gasoline now available trapc riaes at fairlylow temperatures and the carburetor is usually locatedin an atmosphere that is quite not. Therefore, after the engine stops there is a tendency for a quantity, of gasoline inthe fuel chamber to boil away andwhatdoes remain are the heavy ends of the fuel distillation curv so that in coldweather starting is diflijcult. J'Iherefore, evaporation is one cause of a reduced quantity of fuel remaining in the neat chamber available for starting purposes. H e h x g I Furthermore, in most arburet'ors or other charge forming" devices mere r several plugs located below the fuel level.' 'It is ei ztrernely difficult to keep these plugs abselute'ly tight, so after an engine stands for a tim'e there is an additional loss .of fuel due to slight leakages through these plugs; h

The result of 'bothof these conditions is that frequently, after an engine stands idle,- there is too little fuel left in the float chamber avail able for starting, and as at the low cranking speeds used for starting the capacity of fthe normal fuel-pumpis very low, considerable cranking is necessary before fuel is available for starting. In .cold weather this ,lackof fuel and limited cranking ability may make it impossible to start the engine.

Also, insorne cases where fuel injection is to be used a normal floatchamber is, not used, and the main fuel pump unless itis primed -will oper ate very ineificiently and perhaps never would supply the desired fuel flow.

2 .means ofthisinvention, an auxiliary fuel chamber is charged with'fuel during the normal operation of the engine. It is held trapped in this chamber after the engine is stopped. By the normal operation of either the choke or throttle, depending on which system is being used thisaux iliary fuel supply is made available during the starting cycle. This fuel being held in a -closed,chamberretains all the light ends and hence efficient fuel is available for starting po es t a further benefit of this invention is to enable the carburetor to have a float mechanism of very smalicapacity. Thus, after stopping, very little fuel would be caused to. boil and percolate into the intake manifold to make starting difficult while the engine is hot.

Figure I is one diagrammatic form of the invention in which the normal operation of the choke mechanism during starting causes the au giliary fuel supply to be made available.

figure II is another diagrammatic form of the invention in which the normal operation of the throttle mechanism during starting causes the auggi ary fuel supply to be made available.

The following is a description of Figure I.

,I is the main fuel supply tank with a vent 2; engine driven fuel pump is at 3, connected to the tank bypipe 33 and to the carburetor fuel entrancechamber 5 by pipe 3i; check valve 3 is inline 34 to prevent fuel from returning to the I pump or tank; passage Bleads to float chamber Qand is controlled by float needle 1 attached to float t. For reasons of economy and in order to have as little fuel as possible in the float chamher to boi-lavvay or percolate into the intake manifold when the engine is hot and has been stopped; float 8 is of the direct action type and is of novel construction. Float 8 is of two diameters, 39 and 4!},- The small diameter 39 is located below the desired fuel level line and the large diameter 40 above the fuel level line. The conical section 4! connecting the two diameters is at the fuel level line so that as the fuel level rises there is a greater and greater volume of float buoyancy available to effect theclosing of the needle valve 1., The clearance between the diameters 39 and 19 and the walls of the float chamber 9 is held "to ;a minimum to reduce the quantity of fuel in chamber 9. This construction of the float :8 and small volume of fuel in chamber 9 is only possible because of the availability of fuel in auxiliary chamber 23 for starting purposes. Float chamber 9 is connected through jet if! and fuel gassagei I to carburetor fuel discharge nozzle l2 located in carburetor barrel 66. Throttle l3 controls the fiow of fuel to the engine, not shown. Choke valve I1 is pivoted in carburetor entrance in the usual manner, and is operated by button l5 and rod l4 attached to lever l6, which is attached to choke shaft 35. Rod I8 attached to the opposite end of lever I6 is used to operate the valve mechanism of auxiliary fuel chamber 28 in the following manner:

Needle valve 21 controls the opening of passage 38 from chamber 5 to chamber 28. Needle valve 2! is attached to one end of lever 24 which passes through and is attached to and supported by flexible diaphragm 26 in one wall of chamber '5. A spring 25 is attached to lever 24, exerting a pull in the direction of holding valve 21 on its seat.

Bell crank 20 is pivoted at 31. Rod |8 attached to one end of choke lever l6 passes through swivel block H; which is loosely attached to bell crank.

28. 22 is a head on the end of rod [8 and spring 2| is located between head 22 and swivel block I9, normally with a small amount of clearance. When the choke is in normal position, there is also clearance 38 between one arm 23 of hell crank and rod 24 which it engages when the mechanism is operated.

Passage 3| connects the top of auxiliary fuel chamber 28 with float chamber 9 which is vented at 32. Passage 3| is closed by needle valve 30 attached to float 29 when auxiliary fuel chamber 28 is filled with fuel.

Figure II is similar to Figure I, except that the auxiliary needle valve 21 is operated by the throttle in place of the choke mechanism. The description of the new operating mechanism is as follows; the description of the remainder is the same as Figure I and the like parts have the same numbers.

Needle valve 21 is attached to one arm 43 of bell crank 42 pivoted at 44. Rod 41 passes through and is attached to and supported by diaphragm 45 in one wall of chamber 5. One end of rod 41 is attached to bell crank 42 and the other end to lever 48 which is pivoted at 49. Rod 58 is attached to and becomes a part of lever 48. A spring 46 between diaphragm 45 and spring support 56 normally exerts a force to hold needle valve 27 on its seat when throttle valve I 3 is held closed by spring 57.

Throttle valve |3 is attached to throttle shaft 6| at the end of which are attached two levers 53 and 54. Attached to the end of lever 53 is rod 52 which has as a bearing support 5|. The end of rod 52 contacts the end of rod 58 when the throttle I3 has been opened a given amount. When throttle I3 is closed there is a clearance 58 between the end of rod 52 and rod 59.

Lever 54 attached to throttle shaft BI is actuated by rod 55 to open the throttle. It is held in its closed position by the force of spring 51 when throttle rod 55 is not actuated.

The operation of Figure I is as follows:

The parts shown diagrammatically are positioned as they would be after the engine has been idle for some time. When the operator is ready to start the engine, he pulls button l5 attached to rod M. This causes choke valve H to rotate in a counter-clockwise direction, rod [8 is pulled to the left, and button 22 acting on spring 2| which acts on swivel block I9 attached to bell crank 2|] causes bell crank 25 to be rotated in a counter-clockwise direction. The arm 23 is thus caused to contact the end of lever 24 and cause it to rotate in a clockwise direction, tilting its supporting diaphragm 26. The needle 21 attached to lever 24 is thus moved from its seat 4 and fuel in chamber 28 under the pressure of the sealed compressed air in chamber 28 flows through passage 36 into chamber 5 and then through passage 6 past needle valve 1 into float chamber 9. It is prevented from flowing back to tank I because of check valve 4. Float 29 lowers from its seat as far as supports 59 permit, allowing the chamber 28 to be vented so that all thefuel, if necessary, can flow from chamber 28. As soon as the engine starts, valve I1 is partially opened, but needle valve 21 is still held off its seat. Fuel pump 3 will deliver fuel sufiicient to run the engine and also to fiow past open needle valve 21 into chamber 28. As the chamber fills, float 29 is raised, causing the needle valve 30 to shut off passage 3|. As soon as this happens, the trapped air remaining in the top of chamber 28 is compressed until there is in chamber 28 a pressure equal to the pressure delivered by the fuel pump 3. As soon as the engine has warmed up, the choke valve is moved to its open position, rotating bell crank 20 in a clockwise direction. Spring 25 acting on lever 24 will cause it to rotate in a counter-clockwise direction, shutting valve 21 and trapping the auxiliary fuel supply in chamber 28. Clearance 38 permits valve 21 to be held on its seat without interference of arm 23. The fuel will thus be confined in chamber 28 until the choke mechanism is again closed for starting purposes. As float 29 and needle 30 close passage 3|, the fuel stored in 28 should retain its light ends and give good starting results when used.

The operation of Figure II is as follows:

The parts shown diagrammatically are positioned as though the engine was operating at reasonable speed, with the throttle [3 opened in the position shown. Under this condition, rod 52 is in contact with rod 58 attached to lever 48 rotating it in a clockwise direction, which pulls rod 41 to the left, compressing spring 46 and rotating bell crank 42 in a clockwise direction, holding needle valve 21 oif of its seat. The fuel pump 3 is delivering fuel under pressure and auxiliary chamber 28 is filled with fuel. Float 29 has raised and valve 30 has. closed off passage 3|. The air remaining in the top of the chamber 28 is thus trapped andcompressed to a pressure equalling the discharge pressure of the pump.

When it isdesired to stop the engine, throttle I3 is held in closed position by spring 51. Rod 52 is moved outof contact with rod 58 and there is clearance at 58. Spring 46 exerts a force rotating bell crank 42 in a counter-clockwise direction, closing passage with needle valve 21. The fuel in chamber 28 is thus held there as long as the throttle is closed.

When it is desired to start the engine, the throttle is opened and by the action above described needle valve 21 is pulled 01f its seat and fuel in chamber 28 can flow into chamber 5 and then into the float chamber 9, as it cannot return to the: main tank because of check valve 4. From the above description of the operation of the device it is readily understood that a supply of fuel will be trapped during the normal running of the engine and be available for starting the engine through the normal operation of the regular parts of a carburetor or fuel charging device. As shown, the auxiliary fuel supply may be controlled either by the choke mechanism or by the throttle mechanism, in case the choke mechanism is not used with some forms of charge forming devices.

I claim:

1. In combination with a carburetor having a float chamber, an auxiliary fuel chamber located above said float chamber, a chamber common to the inlet of the float chamber and the inlet to the auxiliary fuel chamber, a fuel pump supplying fuel under pressure to said common chamber, a valve controlling the entrance to said auxiliary chamber, said valve being closed when the carburetor throttle is in idle position and open to supply fuel to said float chamber when the throttle is open.

2. In combination with a carburetor float chamber and throttle, an auxiliary fuel chamber located higher than said float chamber, having a fuel inlet, a fuel passage between the fuel inlet to the float chamber and fuel inlet to said auxiliary chamber, a needle valve controlling the inlet to said auxiliary fuel chamber connected to said throttle so that when the throttle i closed said A inlet to auxiliary chamber is closed and open when the carburetor throttle has been partially opened.

3. In combination, an engine, a fuel metering adapted to trap and hold fuelin said auxiliary chamber under pump discharge pressure when said engine is stopped, and to make said fuel available during the starting of said engine.

a. In combination with an engine, a fuel metering device having a float chamber and a choke valve, an auxiliary fuel supply chamber located above said float chamber, a fuel pump to supply fuel to said metering device and said auxiliary chamber through a common chamber connecting said float and auxiliary chambers when the engine is running, a fuel valvecontrolling the flow of fuel to and from said auxiliary fuel supply chamber, a connection between said fuel supply valve and said choke valve whereby said fuel valve is open when said choke valve is partially closed, and closed when said choke valve is open.

5. In combination with a carburetor having a control and a float chamber, an auxiliary fuel chamber, a connecting passage between the inlet of the float chamber and the inlet of the auxiliary fuel chamber, a fuel pump supplying fuel under pressure to said connecting passage, a valve controlling the entrance to said auxiliary chamber, a connection between said valve and said carburetor control adapted to close said valve when said control is in engine non-operating position, and open said valve only when said control i in a normal engine operating position.

6. A carburetor for an internal combustion engine comprising: an air passage having a valve for controlling the flow of air therethrough, liquid fuel supply to said passage, including a main float chamber and a connected auxiliary float chamher, a pump supplying fuel under pressure to both of said chambers, and means for trapping and holding fuel under pump discharge pressure in said auxiliary chamber when said air control valve is in its normal engine non-operating position.

7. A carburetor according to claim 6, wherein said means includes a fuel valve, actuated by said air control valve, for controlling the flow of fuel to and from said auxiliary chamber.

8. A carburetor according to claim 6, wherein said means includes a float-actuated valve in each of said chambers.

9. A carburetor according to claim 6, wherein said means includes a fluid pressure equalizing passage connecting said chambers.

10. A carburetor according to claim 6, including means for supplying the fuel trapped in said auxiliary chamber to said air passage whenever said Valve is in normal position for starting the engine.

11. A carburetor for an internal combustion engine comprising: an air passage having a choke valve, a liquid fuel supply to said passage, including a main float chamber and a connected auxiliary float chamber, a pump supplying fuel under pressure to both of said chambers, and means for trapping and holding fuel under pressure in said auxiliary chamber when said choke valve is in non-operating position.

12. A carburetor for an internal combustion engine comprising: an air passage having a throttle valve, a liquid fuel supply to said passage, including a main float chamber and a connected auxiliary float chamber, a pump supplying fuel under pressure to both of said chambers, and means for trapping and holding fuel under pressure in said auxiliary chamber when said throttle valve is in engine-idling position.

13. A carburetor according to claim 11, wherein said means includes a fuel valve, actuated by said choke valve, for controlling the flow of fuel to and from said auxiliary chamber.

14. A carburetor according to claim 12, wherein said means includes a fuel valve, actuated by said throttle valve, for controlling the flow of fuel into and out of said auxiliary chamber.

MILTON E. CHANDLER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,860,356 Firth May 31, 1932 1,973,162 Briggs Sept. 11, 1934 2,009,648 Carlson July 30, 1935 FOREIGN PATENTS Number Country Date 419,234 Germany Sept. 22, 1925 

